 Quote by tiny-tim
And even light in orbit at exactly 1.5 will be in unstable orbit, and so will either spiral in or spiral out.
But give it a kick radially inwards, from 1.5, and I think it just reaches the opposite point of the orbit with the same kick outwards, and then escapes.  |
Hi tiny-tim.
You're right about the instability, but I think you've got it wrong with the effect of the 'kick'.
For any particle, including light, to move as you described, it must pass a point with pure horizontal (tangential) velocity and with r < 1.5R_hor. Unless it can move at a local speed exceeding c, it will spiral in, don't you think? Look at the 'impact parameter' of MTW.